Shatapatha Brahmana 1.5.1.1

1.5.1.1

sa vai pravarāyāśrāvayati | tadyatpravarāyāśrāvayati yajño vā āśrāvaṇaṃ yajñamabhivyāhṛtyātha hotāram pravṛṇā iti tasmātpravarāyāśrāvayati

He (the Adhvaryu) now utters his call for the Pravara (choosing of the Hotri). The reason why he utters his call, is that the (Adhvaryu's) call is the sacrifice: 'having bespoke the sacrifice, I will choose the Hotri,' thus (he thinks, and) for this reason he utters his call for the Pravara.